Natural Conditioning Factors in the Landscape Modeling of the Ilhabela Archipelago, Brazil

The Ilhabela archipelago, located off the northern coast of São Paulo State, Brazil, is renowned for its remarkable biodiversity. The integration of geospatial data with geological, soil, and vegetation maps has enabled the identification of three distinct regions with notable geomorphological characteristics: the northern, eastern, and southern sectors. Each sector displays a well-defined relief, characterized by dissected, heterogeneous terrain, significant elevations, and steep slopes. These features contribute to the formation of deep valleys and abrupt escarpments. The local geology comprises crystalline basement rocks intruded by several Cretaceous alkaline bodies, which exhibit varying resistance to erosion. These lithological differences have been pivotal in shaping prominent escarpments and sharply defined ridges. The predominantly dendritic surface drainage pattern reflects the interplay between the geological framework and erosion processes, with the main watercourses aligned in NW-SE and NE-SW orientations. The dense Atlantic Forest cover plays a crucial role in protecting soil and stabilizing slopes, acting as a natural barrier against erosion. However, the combination of steep slopes, less erosion- resistant geological units, and a thick weathering layer creates conditions prone to landslides, particularly during heavy rainfall. Identifying highly vulnerable areas under such conditions is essential for effective spatial planning and management. Consequently, continuous monitoring strategies, especially in steeper gradient areas, are strongly recommended to mitigate geological hazards. Furthermore, integrated efforts involving environmental protection, sustainable land management, and community awareness initiatives are vital for reducing the impact of natural disasters while preserving Ilhabela’s rich natural heritage.